The present invention relates generally to a laser scanner that is mounted on a vehicle and used during the vehicle""s forward motion to determine the elevation of the ground surface in front of the moving vehicle by non-contact means, even though the ground surface may be covered by vegetation.
On certain vehicles, such as bulldozers or land mine removing vehicles, it is important to know the elevation and contour of the ground with respect to the vehicle. Vegetation and rocks on the ground make such determinations difficult, because the sensor may sense the tops of vegetation or small rocks instead of the ground surface. As the blade of a bulldozer or land mine removing vehicle moves through the soil, the elevation immediately in front of the blade changes as the loose soil cut by the blade piles up against and is pushed forward by the blade. It is, therefore, necessary to determine the ground elevation of the undisturbed surface at a distance in front of the blade. Land mine removing vehicles have additional difficulties since physical sensors used to sense the elevation of the ground surface may be damaged or destroyed by rapidly expanding gases or flying debris creating by an exploding land mine. Knowing the ground elevation and contour with respect to the dozer blade is very important in order to maintain the blade at the proper depth and angle. If the blade is too shallow, the blade may pass over a land mine, permitting its subsequent detonation under the vehicle and thereby damaging or destroying the vehicle and possibly injuring personnel on board. If the blade is too deep, the forward progress of vehicle is slowed, lengthening the time required to clear the mine field, which could adversely affect the associated military operation, and in some cases may even cause the vehicle to stall. Knowing the ground height or elevation and contour allows for a safer and more efficient use of the vehicle. The xe2x80x9canglexe2x80x9d to which reference is made is that angle between the blade and horizontal, and is achieved by raising or lowering one end of the blade to essentially rotate the blade about the longitudinal centerline of the vehicle. For clarity, that angle will be called the xe2x80x9ctilt anglexe2x80x9d, and movements of the blade to vary the tilt angle will be referred to as xe2x80x9ctiltxe2x80x9d or xe2x80x9ctilting.xe2x80x9d
It is an object of the invention to provide a vehicle with a laser scanner that is able to determine height or elevation of the ground surface and its contour in front of the moving vehicle.
It is another object of the invention to provide a system that can measure ground height or surface elevation and is unaffected by the presence of vegetation.
It is another object of the invention to provide a land mine removing vehicle that is able to detect ground surface elevation and contour by remote, non-contact sensing.
The present invention provides a scanning laser system that is able to temporarily scan through vegetation to determine the elevation of the ground surface with respect to the vehicle.